Center set for clocks

ABSTRACT

A clock hand setting mechanism mounted upon the crystal of a clock and having a manually manipulatable setting stem whose axis is substantially coincident with the axes of the hour, minute, and second hand shafts which extend from the clock movement, the setting stem being adapted for longitudinal movement toward and away from the clock dial, with the extremity of the stem closest to the dial carrying at least one finger displaced from and running generally parallel to the axis of the stem for selectively engaging and rotationally adjusting the second and minute hands of the clock, the second hand being driven by the second hand shaft through a frictional clutch device to prevent damage to the escapement mechanism of the clock movement while the position of the clock hands are being adjusted.

Dinerstein [541 CENTER SET FOR CLOCKS [72] Inventor: Samuel Dinerstein,Lake Geneva,

Wis.

[73] Assignee: The llunker kamo Corporation,

' Oak Brook, lll.

[22] Filed: Feb. 22, 1971 [21] Appl. No.: 117,532

[52] US. Cl. ..58/85.5 [51] Int. Cl. ..G04b 27/00 [58] Field of Search..58/63, 73, 85.5, 126 D [56] References Cited UNITED STATES PATENTS2,607,188 8/ 1952 Bourquin ...58/85.5 1,824,781 9/1931 La Bar ..58/85.'5UX 3,142,148 7/1964 Morgan et al ..58/126, D 1,138,690 5/1915 RypinskL,..58/85.5 UX 2,564,103 8/1951 7 Gallagher ..58/85.5 UX 1,982,495 11/1934Browning "58/855 X FOREIGN PATENTS OR APPLICATIONS 13,953 10/1915 GreatBritain ..58/l26 1) [151 3,696,607 [451 Oct. 10, 1972 702,060 3/1931France .....58/85.5

Primary Examiner-Richard B. Wilkinson Assistant Examiner-George H.Miller, Jr. Attorney-Frederick M. Arbu'ckle [57] ABSTRACT the clock, thesecond hand being driven by the second hand shaft through a frictionalclutch device to prevent damage to the escapement mechanism of the clockmovement while the position of the clock hands are being adjusted.

10 Claims, 6 Drawing Figures PATENTEDncr 10 I972 CLOCK MOVEMENTESCAPEMENT MEANS Inve ntor Samuel pl nersteln.

CENTER SET FOR CLOCKS BACKGROUND OF THE INVENTION In the prior art,clocks having manually manipulated hand setting mechanisms mounted at acentral location upon the clock crystal are well known. Generally asetting stem is journaled within an aperture in the clock crystal suchthat the axis of the stem is substantially coincident with the axes ofthe hour and minute hand shafts extending from the clock movement. Theminute hand shaft is generally a solid rod joumaled within a tubularhour hand shaft. A knurled knob is affixed to the extremity of thesetting stem which is external to the clock crystal while the internalextremity of the stem is shaped to engage a splined receptacle or thelike in the end of the solid minute hand shaft of the clock movement.The setting stem is further adapted for longitudinal movement along itsaxis and is spring biased to a normal rest position at which theinternal extremity of the stem is out of engagement with the minute handshaft.

To adjust the setting of the hands of such prior art clocks, one needonly grasp the knurled knob on the setting stem, push the stem inwardlyuntil it engages the minute hand shaft and then rotate the knob untildesired setting of the clock hands is achieved.

While such a prior art center set arrangement is useful with clocksutilizing only hour and minute hands, it has inherent limitations inrespect of clocks provided with second hands. In most instances thesecond hand is driven from a shaft which is coaxial with the tubularminute and hour hand shafts of the clock movement. Since the second handis coupled to the second hand shaft by a hub which extends into thetubular minute hand shaft and grasps the second hand shaft, directaccess to the minute hand shaft is not available. Moreover in clockshaving such top mounted" second hands, it is not practical to attemptsetting the clock hands by directly engaging the second hand itself orthe second hand shaft since the direct gearing of the second hand shaftto the internal clock movement shaft on which the escapement wheel ismounted would cause bending of the escapement pins if substantial manualrotational force were to be applied to the second hand shaft.

Clock mechanisms with top mounted second hands have considerable appealto the public and those with remote setting mechanisms have been soldextensively. Therefore, the development of a mechanism adjustable from acenter set mounted on the clock crystal is desirable for use with clockshaving a top mounted second hand.

- SUMMARY OF THE INVENTION This invention is directed to a clock havinga manually manipulatable clock hand setting mechanism mounted on theclock crystal and wherein the clock is provided with a top mountedsecond hand. The hand setting mechanism includes means for controllingthe position of the second hand relative to the axis of the second handshaft. More particularly, the invention is directed to a clock whereinthe manually manipulatable clock hand setting mechanism is positioned ona crystal in front of the second hand. The invention is also directed tothis type of clock in which a frictional coupling is interposed betweenthe second hand and 2 the escapement means to avoid damage to theescapement means when the second hand is manually positioned.

More specifically the invention is directed to a clock with hour, minuteand second hands wherein the manually manipulatable clock hand settingmechanism is rotatable from a position external to the crystal and isconnected to an engagement means for selective engagement and rotationaladjustment of the second and minute hands of the clock. The features ofthe clock are particularly advantageous in respect to top mounted secondhand arrangements requiring selective adjustment of the second andminute hands without damage to the escapement means. In addition,connection means are associated with the engagement means to permittransverse movement of the engagement means with respect to the axis ofthe second hand shaft. This feature enables the engagement means to moveto the side of the second hand when initial contact is made on the frontsurface of the hand. Otherwise, continued force applied to theengagement means would result in bending of the second hand, the secondhand shaft, associated linkages and possibly the minute hand.

In accordance with the present invention a clock is provided which has amanually manipulatable clock hand setting mechanism and includes incombination a clock movement with at least a second hand shaft extendingtherefrom for driving a time indicating hand affixed to the shaft. Theshaft is mechanically coupled to an escapement means integral with theclock movement. A manually manipulatable means is provided forselectively engaging the second hand for controlling its position aboutthe axis of the second hand shaft. A torque limiting clutch means isinterposed between the second hand and the escapement means to preventdamage to the escapement means during adjustment of the second hand.Preferably the clock is constructed with a center set mechanism havingbuilt-in rotational lost motion or mechanical play, in respect of thesecond hand shaft axis to permit the engagement means to move off to theside of the second hand or minute hand in the event that the engagementmeans is forced against the front surface of either hand. Also, thefront surface of the second hand is shaped to encourage movement of theengagement means to the side of the hand in the event that contact ismade. Still further in accordance with the present invention the secondhand is resiliently coupled to its shaft to permit some movement of thesecond hand towards the dial in the event that the engagement meansfails to move to the side of the hand.

DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a front view (without crystal) of an automobile clockillustrating the dial and hands.

FIG. 2 is an expanded view of the coaxially mounted shafts of themovement and the second, minute; and hour hands.

FIG. 3 is a section taken along the line 3-3 of FIG. 2 showing bycross-section the shape of the second hand designed to force the fingerto the side.

FIG. 4 is a section view along the axis of the center set and thecoaxially mounted shafts showing a finger arrangement wherein twofingers are peripherally mounted on a plate and includes a block diagramrepresenting conventional escapement means of the movement connected tothe second hand shaft.

FIG. 5 is a similar view of the center set mechanism and illustrates aplate which utilizes one finger.

FIG. 6 is a side view of a plate showing the shape of the finger shownin FIG. 5. I

GENERAL DESCRIPTION The invention is directed to a clock having amanually manipulatable'clock hand setting mechanism and including incombination a clock movement having at least a second hand shaftextending from the movement for driving a time indicating hand affixedto the shaft. The shaft is mechanically coupled to an escapement meanswithin the clock movement. The manually manipulatable means serves tocontrol the position of the hand relative to the axis of the second handshaft. A torque limiting clutch means is interposed between the secondhand and the escapement means to prevent damage to the escapement meansduring positioning of the second hand. The clock has a crystalpositioned in front of the second hand and the manually manipulatablemeans comprises a rotable means which extends through an opening in thecrystal and is connected to an engagement means positioned beyond theperiphery of the second hand shaft and directed towards the second handof the clock. Usually, hour and minute hands are present and the rotablemeans and engagement means are movable towards the hands to selectivelyengage and rotationally adjust the second and minute hands of the clock.

In more detail, the clock has a movement and a casing for the movementincluding a dial and crystal. The dial has a centrally located openingin which hour, minute and second hand shafts of the movement arecoaxially mounted with respect to one another. I-Iour, minute and secondhands each are mounted on one of the shafts with the hour hand beingpositioned closest to the dial. The movement includes escapement meanswhich is connected to the second hand shaft and frictional torquelimiting means are interposed between the second hand and the escapementmeans.

The crystal is positioned in front of the dial and has an openinglocated directly in front of the shafts. Engagement means are located ina normal rest position immediately adjacent the inner surface of thecrystal, with one or more fingers extending beyond the periphery of theshafts and extending toward the hands of the clock. Rotable meansextending through the crystal opening are connected to the engagementmeans and are movable towards the hands to selectively engage androtationally adjust the second and minute hands of the clock. Means arealso provided for biasing the rotable means and engagement means totheir normal rest position. In the combination of engagement means androtable means, connection means are provided to permit transversemovement of the engagement means with respect to the axis of the secondhand shaft. This movement can be in the form of lost-motion ormechanical play" to permit the finger or fingers of the engagement meansto move to the side of the second or minute hand in the event thatcontact is made with the front surface of either hand. In addition thefinger or fingers are advantageously constructed of flexible materialand the resultant resilience of the finger prevents damage to the secondhand and second hand shaft. Similar benefits in respect of the minutehand are also obtained. In addition each finger when positioned over ahand is transverse to the axis of the hand and lays generally in a planewhich is skewed relative to this axis. Also, the two opposing side wallsof the finger generally along the periphery of the plate are taperedtowards the clock hand and the tip of the finger is rounded. Thesefeatures enable the resilient finger to move to the side of the handwhen contact is made with the front surface of the hand and particularlywhen such surface is in the form of an inverted V or other form with anapex which aids in the lateral movement of the finger.

In more particularity attention is now directed to FIG. 1, in which aclock 10, is shown including a casing 12 for housing the clock movementand a dial 14 with time indicia delinated thereon. Centrally located hub16 is mounted on the shaft for the second hand 18 (as more completelyillustrated in FIG. 4). Second hand 18, minute hand 20, and hour hand 22are also illustrated.

FIG. 2 is an enlarged view of the hub and underlying coaxially mountedshafts. As illustrated, front hub 16 is mounted on inner shaft 24 andtop mounted second hand 18 is frictionally and resiliently mounted tothis arrangement. Minute hand 20 is rigidly attached to shaft 26 in acustomary manner. As with conventional clocks, shaft 26 of the movementis interconnected with associated linkages to hour hand 22 so thatmotion of the minute hand 20 provides controlled movement of the hourhand 22. Hour hand 22 as illustrated in FIG. 2 is connected to outershaft 28.

FIG. 3 illustrates a sectional view of the second hand 18 showing theouter surface 30 shaped to force the finger to the side of the hand inthe event that thefinger is forced against the outer surface of thehand. As illustrated, the shape is in the form of an inverted V althoughother forms such as an inverted U and the like may be utilized. Minutehand 20 also is advantageously designed with a similar cross sectionalthough considerably thicker.

Turning now to FIG. 4, there are illustrated three coaxially mountedshafts 24, 26 and 28, corresponding to the second-hand shaft, theminute-hand shaft and the hour-hand shaft of the clock movement.Secondhand 18, minute-hand 20 and hour hand 22 are respectively mountedto these shafts. The second-hand shaft 24 is generally directly gearedto the clock movement escapement means as indicated by the dotted line67 extending therefrom to the block 29.

With further reference to FIG. 4, and more particularly the lefthandportion thereof, the manually manipulatable clock hand setting mechanismof the present invention is illustrated. A setting stem 32 shown in itsnormal rest position extends through an opening 34 of the clock crystal36. The axis of the setting stem 32 is substantially coincident with theaxes of the shafts 24, 26 and 28. At the righthand or internal extremityof the stem 32 a plate 38 is loosely coupled to a turned down reduceddiameter portion of the stem 32. The plate 38 carries fingers 40 and 42which are spaced apart so as to engage the second-hand l8 and theminute-hand 20 when the stem 32 is urged toward the clock hands. Theplate 38 is captured on the turned down portion of the stem 32 bysuitable means such as the enlarged portion 44 which can be formed bypeening the material comprising the shaft 32 after the plate 38 has beenmounted thereon. The mechanical coupling between the plate 38 and thestem 32 is made purposely loose so that if the fingers 40 and 42directly engage the surface of either the second-hand or minute-hand,the fingers will tend to slide off to one side or the other of'the handsas generally described in connection with FIG. 3. In this regard it ispreferable to mount the plate 38 on the stem 32 such that somerotational lost motion is permitted between the plate 38 and the stem 32when the latter is rotated. This may be accomplished by a variety ofmeans such as for example indicated by the key 45 shown in dotted lines.The slot with which the key cooperates is made substantially larger thanthe width of the key. Additionally, the plate 38, although normallyresting in a plane parallel to the inner surface of the clock crystal38, may be easily skewed. This freedom of motion is ensured by makingthe diameter of the hole in the plate somewhat larger than the diameterof the turned down portion of the stem 32. This ensures that in theevent both fingers 40 and 42 fall upon the same side of both arms of thesecond or minute-hand, the forcing of the stem 32 toward the bands willnot tend to bend the hands.

With further reference to FIG. 4 it can be seen that the set stem 32 isbiased by spring 50 acting upon the inner surface 48 of the set knob 46to a normal rest position at which the fingers 40 and 42 are disengagedfrom the hands of the clock. One end of the spring 50 engages thesurface 52 of the set knob 46, while the other end of the spring 50rides against the surface of a boss 54 on the crystal 36. The length ofthe stem 32 is so established as to permit longitudinal movement of thefingers 40 and 42 to a position adjacent either the second-hand 18 orthe minute-hand 20 without reaching the hour-hand 22. Movement of theminutehand, of course, will cause the desired movement of the hour-hand22 when setting the hands of the clock.

In further accordance with the present invention and as illustrated inFIG. 4, the second-hand 18 is frictionally and resiliently coupled tothe second-hand shaft 24. This obviates damaging the second-hand in theevent that the fingers 40 and 42 engage the same on its upper surfacewithout sliding off to either side thereof while the stem 32 is forcedin a direction to engage the minute-hand 20, and at the same timeobviates damage to the clock movement escapement means when thesecond-hand 18 is rotated by the fingers 40 and 42. To this end thespring 60 serves as a biasing means and forces the second-hand 18 at thesurface 58 thereof to form a frictional torque restraining clutchmechanism with the surface 62 of hub 16. The end 63 of spring 60 in turnacts against the flange 64 which is affixed to the hub by a suitablemeans such as upsetting the periphery of the hub or the like. Thespacing between the surface 62 of the hub 16 and the surface of flange64 against which the spring 60 acts is such as to permit the second-handto be tilted away from its normal rest position to an extent where theend of the second-hand comes into close juxtaposition to but does nottouch the surface of the minute-hand. This degree of play is generallysufficient to prevent either the bending of the second-hand itself orthe second-hand shaft 24 when the fingers fail to slip off to the sidesof the hand.

A still further embodiment of the present invention is shown in FIG. 5which is in all respects substantially identical to the arrangementshown in FIG. 4 except that only one finger shown at is attached or madeintegral with the plate 71. This obviates the possible bending of thehand as is inherent with the use of two fingers when falling on the sameside of the hand. In this embodiment the plate 71 can be fitted to thestem 32 with closer tolerances so as to minimize the transverselooseness of the plate upon the stem 32 as by making the diameter of thehole in the plate 71 closer to the diameter of the reduced portion ofthe pin 32.

Still further in accordance with the present invention, and asillustrated in FIGS. 4 and 5, it can be seen that the plane in whicheach of the fingers 40, 42 and 70 generally lay is skewed relative tothe axes of the stem 32. The fingers are accordingly made of a flexiblematerial such as polypropylene, polyethylene, nylon or the like andsufficiently thin so that in the event the fingers directly engage thesecond-hand 18 or the minutehand 20, they will tend to yieldlongitudinally along the axes of the hands and exert a force thereonless than that required to permanently bend the hands.

Turning now to FIG. 6 there is there illustrated a side view of fingers70 showing the taper of the side 72 and the curved surface of the end74. This configuration may, of course, be used in connection with thefingers 40 and 42 shown in FIG. 4. Finger 70 is positioned (asillustrated in FIG. 4) with the taper 72 and and curved or rounded end74 being in the direction of second hand 18. These features cause finger70 to move to the side of second-hand 18 or to move hand 18 in a lateraldirection with respect to finger 70. The taper 72 and 75 is controlledto avoid excessive taper and the development of a binding force againsthand 18. Preferably there is less finger taper in the vicinity of theminute hand to ensure a more positive setting drive thereon as shown at72a in FIG. 6.

The foregoing description of the present invention is only illustrativeof an exemplary form which the invention may take. Still, othermodifications and variations will suggest themselves to persons skilledin the art. It is intended, therefore, that the foregoing detaileddescription be considered as exemplary only and that the scope of theinvention be ascertained from the following claims.

What is claimed is:

1. A clock having a movement, a casing for the movement including a dialand a crystal, the crystal having a centrally located opening, saidmovement including hour, minute and second hand shafts coaxially mountedwith respect to one another andescapement means connected to the secondhand shaft, said shafts extending to the front of the dial, an hour, aminute, and a second hand each respectively mounted on a correspondingone of said shafts, with the hour hand closest to the dial, frictionaltorque limiting means interposed between the second hand and saidescapement means, said crystal being positioned in front of the dialwith said opening located directly in front of said shafts, engagementmeans normally positioned adjacent the inner surface of said crystalbeyond the periphery of the shafts and extending toward the hands of theclock, rotatable means extending through said crystal opening, connectedto said engagement means and movable toward the hands to selectivelyengage directly and rotationally adjust the second and minute hands ofthe clock.

2. A clock according to claim 1 wherein said second hand is top mountedin respect to said hour and minute hands.

' 3. A clock according to claim 1 which includes means for biasing therotatable means and engagement means to their normal position away fromsaid hands.

4. A clock according to claim 1 wherein the engagement means comprisesat least one finger connected to the rotatable means.

5. A clock according to claim 4 wherein said finger is differentiallytapered along its sides with less taper along those portions thereofwhich are adapted to engage the minute hand.

6. A clock according to claim 1 wherein the front surface of said secondhand is shaped to produce movement of said engagement means when theengagement said rotatable and engagement means including connectionmeans to permit transverse movement of the engagement means in respectto the axis of the second hand shaft.

7. A clock according to claim 6 wherein the clock includes means forbiasing the rotatable means and engagement means to their normalposition away from said hands, said engagement means comprises at leastone flexible finger connected to the rotatable means, and said secondhand is mounted on top of said hour and minute hands.

8. A clock according to claim 7 wherein the second and minute hands haveouter surfaces shaped to force said finger in a transverse directionwhen the finger is forced against the front surface of either hand, andsaid finger is constructed of a flexible material.

9. A clock according to claim 7 wherein said frictional torque limitingmeans is interposed between said second hand and said second hand shaftand said finger is in a plane skewed in respect to said stem.

10. A clock according to claim 9 wherein said second hand isfrictionally and resiliently coupled to said second hand shaft.

1. A clock having a movement, a casing for the movement including a dialand a crystal, the crystal having a centrally located opening, saidmovement including hour, minute and second hand shafts coaxially mountedwith respect to one another and escapement means connected to the secondhand shaft, said shafts extending to the front of the dial, an hour, aminute, and a second hand each respectively mounted on a correspondingone of said shafts, with the hour hand closest to the dial, frictionaltorque limiting means interposed between the second hand and saidescapement means, said crystal being positioned in front of the dialwith said opening located directly in front of said shafts, engagementmeans normally positioned adjacent the inner surface of said crystalbeyond the periphery of the shafts and extending toward the hands of theclock, rotatable means extending through said crystal opening, connectedto said engagement means and movable toward the hands to selectivelyengage directly and rotationally adjust the second and minute hands ofthe clock.
 2. A clock according to claim 1 wherein said second hand istop mounted in respect to said hour and minute hands.
 3. A clockaccording to claim 1 which includes means for biasing the rotatablemeans and engagement means to their normal position away from saidhands.
 4. A clock according to claim 1 wherein the engagement meanscomprises at least one finger connected to the rotatable means.
 5. Aclock according to claim 4 wherein said finger is differentially taperedalong its sides with less taper along those portions thereof which areadapted to engage the minute hand.
 6. A clock according to claim 1wherein the front surface of said second hand is shaped to producemovement of said engagement means when the engagement means contacts thefront surface of the second hand, said second hand shaft having alongitudinal axis, and said rotatable and engagement means includingconnection means to permit transverse movement of the engagement meansin respect to the axis of the second hand shaft.
 7. A clock according toclaim 6 wherein the clock includes means for biasing the rotatable meansand engagement means to their normal position away from said hands, saidengagement means comprises at least one flexible finger connected to therotatable means, and said second hand is mounted on top of said hour andminute hands.
 8. A clock according to claim 7 wherein the second andminute hands have outer surfaces shaped to force said finger in atransverse direction when the finger is forced against the front surfaceof either hand, and said finger is constructed of a flexible material.9. A clock according to claim 7 wherein said frictional torque limitingmeans is interposed between said second hand and said second hand shaftand said finger is in a plane skewed in respect to said stem.
 10. Aclock according to claim 9 wherein said second hand is frictionally andresiliently coupled to said second hand shaft.